The output is telling there are no hits. It could be due to the time window or an error in the query.

I would also recommend that you use a "Values" call instead of a "Query" one, just pick an indexed key and get the values for that key, make sure it is something like "medium" which differentiate between hits on packets and logs but since your query is for log data only that would work, alternatively use something like device.type as again it's something that you are forcing to be unique in your result set.

"Values" calls are normally more efficient than "Query" calls due to their nature of running only against a key index vs the entire meta DB.